基于大物流分形的X方物流结构与优化

本文认为,大物流存在自相似嵌套式PMF分形结构,分形单元的集合便构成了X方物流,这是其形成的内在本质和规律;大物流环境特别是企业与客户关系的深刻变革,供应链中各方主体物流业务活动向对方领域不断扩展和渗透,从而形成了多方物流(XPMF)自治与合作的情形,这是X方物流形成的外在需求动力。文章提出,X方物流通过分形单元在其活动空间的调整和重构,建立自组织和自优化机制,可以实现X方物流动态结构优化,从而为委托企业提供基于PMF分形集合的供应链物流解决方案。

现代物流与传统物流的基础理论研究

本文认为,物流性质划分为固有性质和非固有性质,物流非固有性质的“传统/现代”特性被定义为“传统物流/现代物流”。文章以物流时间维、物流性质维和物流特征维构建物流发展状态三维结构模型,阐述传统物流与现代物流的辩证关系,指出传统物流、现代物流、传统/现代物流相互转换这三种模式是各个国家各个时期的客观存在,它们在不同国家不同时期有不同的构成。

大物流再论

本文在"大物流论"五个主要理论"物的流动论"、"综合物流论"、"大物流科技论"、"大物流工程论"和"大物流产业论"基础上,新提出了"物流要素论"和"物流性质论"。物流要素论认为,无论自然界、社会界和经济界的物流都是由物质、流动、主体、地域和时间五个基本要素组成的,即MFORT理论,五要素中物质是核心要素。物流性质论提出物流有固有和非固有两种性质。物流固有性质反映物流基本要素的本质特征,是物流具有的不以人们主观意志为转移的客观性质。物流非固有性质反映物流非基本要素的非本质特征,可以依据物流运作主体的主观意愿进行选择。物流固有性质有五个:物质性、流动性、主体性、地域性和时间性;物流非固有性质也有五个:主体性、服务性、管理性、技术性和经济性。

传统物流向现代物流转化模型研究

依据大物流性质理论,构建物流发展状态三维结构,并用MF=(SMTE,C,V(t))有序三元组作形式化表达。物流主体通过制定策略D,使物流非固有性质SMTE发生关于特性C的量值V(t)的变化,表现为关联函数K(MF)在可拓集合上的变动,由此可以识别物流三种状态,即传统物流、现代物流以及传统物流向现代物流转化。

Rheological and mechanical properties of wood fiber-PP/PE blend composites

For evaluation of the rheological and mechanical properties of highly filled wood plastic composites （WPCs）, polypropylene/polyethylene （PP/PE） blends were grafted with maleic anhydride （MAH） to enhance the interfacial adhesion between wood fiber and matrix. WPCs were prepared from wood fiber up to 60 wt.% and modified PP/PE was blended by extrusion. The rheological properties were studied by using dynamic measurement. According to the strain sweep test, the linear viscoelastic region of composites in the melt was determined. The result showed that the storage modulus was independent of the strain at low strain region （〈0.1%）. The frequency sweep resuits indicated that all composites exhibited shear thinning behavior, and both the storage modulus and complex viscosity of MAH modified composites were decreased comparing to those unmodified. Flexural properties and impact strength of the prepared WPCs were measured according to the relevant standard specifications. The flexural and impact strength of the manufactured composites significantly increased and reached a maximum when MAH dosage was 1.0 wt%, whereas the flexural modulus after an initial decreased, also increased with MAH dosage. The increase in mechanical properties indicated that the presence of anhydride groups enhanced the interracial adhesion between wood fiber and PP/PE blends.

Physical and Hydrodynamic Properties of Spherical Cellulose-Titanium Dioxide Composite Matrix for Expanded Bed Adsorption

Expanded bed adsorption (EBA) has been widely used in industrial downstream bioprocessing. Solid matrix is the principal pillar supporting the successful application of EBA. A novel spherical cellulose-titanium dioxide composite matrix was prepared through the method of water-in-oil suspension thermal regeneration. Its typical physical properties were wet density 1.18g.cm-3, diameters in the range of 100-300um, porosity 85.5%, and water content 72.3%. Expansion characteristics and liquid mixing performance of the matrix in expanded bed were investigated using water and 10% (by mass) glycerol solution as mobile phases. The results indicate that the custom-assembled matrix has a stable flow hydrodynamics and exhibits the same degree of liquid-phase mixing or column efficiency as the commercially available Streamline adsorbent.

Experimental Investigation on Flow and Scour Characteristics Around Tandem Piers in Sandy Channel With Downward Seepage

Experimental investigations have been carried out to study morpho-hydraulic characteristics such as scour geometry and turbulent flow properties around tandem piers in alluvial channels. Experiments were carried out in a plane sand bed with two circular piers of same diameter arranged in tandem manner under no seepage, 10% seepage and 20% seepage conditions. Downward seepage minimizes the scour depth around piers and restrains the development of scour depth with time. Strong reversal flow is found near the bed at upstream of piers and near free surface at downstream of piers where velocity and Reynolds shear stress are found to be negative which reduce in magnitude with downward seepage. The flow is more critical within the gap between two piers where velocity is lesser near free surface and gradually increasing towards bed. Quadrant analysis shows that contribution of each event to the total Reynolds shear stress increases with downward seepage. Sedimentation effect prevails within the scour hole whereas outside the scour hole erosive forces become more dominant. Reduced reversal flow at upstream of pier because of downward seepage results in decreasing higher order moments and turbulent kinetic energy. At downstream of piers, secondary currents are dominant due to wake vortices. Strouhal number decreases in case of seepage runs than no seepage condition.

Liquid film falling behaviour on horizontal circular cylinder

The flow pattern behaviour of falling liquid film over three horizontal cylinders was evaluated.These flows can take three forms:discrete droplets,individual jets,and continuous sheet,and special attention is paid to the effects of the physical properties and geometrical parameters of the first two forms(droplets and jets) because these forms are more important in heat-transfer behaviour and less research has been published for these forms,The flow modes and experimental results were successfully compared with previous experimental literatures,and also the effects of liquid flow rate,tube diameter,and tube spacing on departure site spacing,in both drop and jet modes,were evaluated in the low Galileo number and high viscosity fluid(cooking oil),to help developing criteria for determining falling film modes and their transitions,and to understand the heat transfer characteristics associated with each mode.

New application notion of pipeline transport——integrated in industry solid waste innocuous and efficient disposition

In order to solve transport problems of industry solid,firstly,a new applicationnotion of pipeline transport was presented,that is to say,combining pretreatment andtransport with disposal techniques of industry solid waste.Secondly,the integrated dis-posal and transport system for industry solid waste was introduced,in particular,the oper-ating principles,equipment set-up,key technology and technical parameters.Next,thispaper illustrated the application of this integrated system.Such as it can transport coalsludge with sufficiently high solids content(about 72%～77%)and high apparent viscosity(about 1 000～3 000 Pa.s)directly by pipeline having no use for water and addition agent.Generally,the transport distance is about 1 000 m.This system has been successfullyused in innocuous disposition and efficient utilization of other industrial byproducts or solidwastes,such as city sludge and paper making waste.The integrated system causes nopollution to the environment for its complete seal and realizes protecting the environment,conserving the energy,promoting the development of cycling economic.Finally,the paperdiscussed the research works that were needed for studying such pipeline transport sys-tem and narrates the relevant condition and application status.

Drug-induced liver injury in hospitalized patients with notably elevated alanine aminotransferase

AIM： To identify the proportion, causes and the nature of drug-induced liver injury （DILI） in patients with no- tably elevated alanine aminotransferase （ALT）. METHODS： All the inpatients with ALT levels above 10 times upper limit of normal range （ULN） were ret- rospectively identified from a computerized clinical laboratory database at our hospital covering a 12-mo period. Relevant clinical information was obtained from medical records. Alternative causes of ALT eleva- tions were examined for each patient, including bili- ary abnormality, viral hepatitis, hemodynamic injury, malignancy, DILI or undetermined and other causes. All suspected DILI cases were causality assessed usingthe Council for International Organizations of Medical Sciences scale, and only the cases classified as highly probable, probable, or possible were diagnosed as DILI. Comments related to the diagnosis of DILI in the medical record and in the discharge letter for each case were also examined to evaluate DILI detection by the treating doctors. RESULTS： A total of 129 cases with ALT 〉 i0 ULN were identified. Hemodynamic injury （n = 46, 35.7%）, DILl （n = 25, 19.4%） and malignancy （n = 21, 16.3%） were the top three causes of liver injury. Peak ALT val- ues were lower in DILI patients than in patients with hemodynamic injury （14.5 5.6 ULN vs 32.5 ：I： 30.7 ULN, P = 0.001）. Among DILI patients, one （4%） case was classified as definite, 19 （76%） cases were clas- sified as probable and 5 （20%） as possible according to the ClOMS scale. A hepatocellular pattern was ob- served in 23 （92%） cases and mixed in 2 （8%）. The extent of severity of liver injury was mild in 21 （84%） patients and moderate in 4 （16%）. Before discharge, 10 （40%） patients were recovered and the other 15 （60%） were improved. The improved patients tended to have a higher peak ALT （808 ＋ 348 U/L vs 623 ＋ 118 U/L, P = 0.016） and shorter treatment duration before discharge （8 ＋ 6 d vs 28 ~ 12 d, P = 0.008） compared with the recovered patients. Twenty-two drugs and 6 herbs were found associated with DILl. Antibacterials were the most common agents causing DILI in 8 （32%） cases, followed by glucocorticoids in 6 （24%） cases. Twenty-four （96%） cases received treatment of DILl with at least one adjunctive drug. Agents for treatment of DILI included anti-inflammatory drugs （e.g., glycyr- rhizinate）, antioxidants （e.g., glutathione, ademetionine 1,4-butanedisulfonate and tiopronin）, polyene phospha- tidyl choline and herbal extracts （e.g., protoporphyrin disodium and silymarin）. Diagnosis of DILl was not mentioned in the discharge letter in 60% of the cases. Relative to prevalent cases and cases from wards of internal medicine, incident cases and cases from surgi- cal wards had a higher risk of missed diagnosis in dis- charge letter [odds ratio （OR） 32.7, 95%CI （2.8-374.1）,CONCLUSION： DILI is mostly caused by use of anti- bacterials and glucocorticoids, and constitutes about one fifth of hospitalized patients with ALT 〉 10 ULN. DILI is underdiagnosed frequently.

Physicochemical properties and heavy metals leachability of fly ash from coal-fired power plant

The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined： the micro-morphology, the mineral composition and the content of heavy metals. The results show that the fly ash from plants using a circulating fluidized bed are more irregular par- ticles, while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape. Quartz and mullite are the main crystalline phases in the ash. Clearly, both the technology and the coal used by a power plant can influence the mineral composition of the ash. The mineral composition of fly ash from a circulating fiuidized bed is more complex than that from a pulverized coal-fired boiler. The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant. Heavy metals are likely to be enriched in the fly ash. Heavy metal leachability was studied using two leaching methods. The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards. But Ni concentrations in the leachates from both batch and column tests exceed the standard. The highest excess rates in both tests were 572~ and 497~, which levels might threaten the environment.

Formation and evolution of Emeishan basalt saprolite in vadose zones of Touzhai landslide source rockmass

In order to explain the formation process of slope hazards, and to identify the key factors leading to instability of a slope, Emeishan basalt saprolite in vadose zones of the Touzhai landslide in Zhaotong, Yunnan, was studied. The formation and evolution of Emeishan basalt saprolite was examined using, amongst other techniques, field investigations,thin section analysis, scanning electron microscopy(SEM) observations, chemical analysis, physical and water-physical property tests of rock masses. Field observations revealed that the majority of the weathered rock blocks were presented as a concentric layer structure in which an internal corestone was enveloped with several layers of external saprolized crust. Chemical and mineralogical analysis identified that iron was the most sensitive element and that the weathering progress usually started with the oxidation of Fe2+ to Fe3+ in rock blocks. Alkaline elements such as Si, Ca, Mg, Na and K were also dissolved and Fe and Al were concentrated in saprolized crusts. Results indicated that loss on ignition(LOI) also increased significantly. SEM results showed that the weathering intensity of thebasalt blocks decreased gradually from the outside to the inside, and the mineral morphology significantly differed on both sides of the weathering front. The saprolized crusts presented cellular microstructure features due to the generation of micropore and clay minerals. Thin section analysis showed that plagioclase was relatively more stable than pyroxene and chlorite during weathering. With a centripetal propagation of the weathering front, saprolized crusts became thicker and corestones became smaller; fresh Emeishan basalt blocks gradually turned into saprolized blocks. Due to the loose structure and low strength of saprolite, the quality of the Emeishan basalt mass significantly deteriorated, this being a potentially important factor which caused the Touzhai landslide to occur.

HIGH EMISSION PERFORMANCE IMPREGNATED DISPENSER CATHODE

In order to obtain higher emission performance than that of a traditional M-type cathode, we have developed a new type impregnated dispenser cathode. The new cathode is impregnated with a new active substance with molar ratio of 26BaO·29SrO·8Sc2O3 ·7CaO·Al2O3 . This paper introduces the emission performance, surface active material, and work function of the new cathode. At 1100℃B , the DC current density and pulse current density are 30.6±1.0 A/cm2 and 171.6±2.8 A/cm2 , respectively, 2.1 and 5.4 times of that of an M-type cathode. The work function of the new cathode is 1.668± 0.002 eV. High concentration O-Al-Sc-Sr-Ba and O-Al-Sc-Ba are found in the pores and at pore edges, respectively. By comparing the emission performances and surface characteristics of as-polished and as-cleaned cathodes, it is proposed that, the emission around pore ends forms the major part of the total emission for the new cathodes.

Shale gas exploitation with supercritical CO_2 technology

This paper analyzes the physicochemical properties of supercritical C02, the characteristic of shale gas and shale gas reservoirs. The technologies of drilling, production, fracturing using the supercritical CO2 in shale gas explo- ration are proposed, to increase the penetration rate, decrease the damage to formation while fracturing, and enhance the recovery of shale gas. It is believed that the huge economic benefits of shale gas exploration with the supercritical CO2 fluid will be obtained, and it also can initiate a new technology field of CO2 in the petroleum engineering.

A Micro-Mechanism Model for Porous Media

Based on the tortuous-expanding path/channel model,a micro-mechanism model for porous media is developed.The proposed model is expressed as a function of tortuosity,porosity,resistance coefficient,and fluid properties.Every parameter in the proposed model has clear physical meaning.The results show that the model predictions are ingood agreement with those from the existing experimental data.

Natural convection heat transfer of molten salt in a single energy storage tank

Heat transfer in molten salt in a cylinder tank is studied via simulation and experiment to obtain its natural convection heat transfer in a single energy storage tank. Simulation and experimental results show that the natural convection heat transfer of water in a cylinder tank fits well with Garon＇s correlation. However, significant deviations occur when Garon＇s correlation is used to predict the natural convection heat transfer of molten salt because of its high viscosity and low thermal conductivity. However, the simulated data of the natural convection heat transfer of molten salt fit well with those of the experimental results Thus, a correlation that considers the effect of variable physical properties is proposed in this study to predict the natural con- vection heat transfer of molten salt. The deviation of the present data from the proposed correlation is less than ＋20%. The re- sults of this study can serve as a basis for the design of single energy storage tanks.

Highly efficient oxygen evolution and stable water splitting by coupling NiFe LDH with metal phosphides

It is a great challenge to develop highly active oxygen evolution reaction(OER)electrocatalysts with superior durability.In this study,a NiFe layered double hydroxidedecorated phosphide(NiFe LDH@CoP/NiP_(3))was constructed to display satisfactory OER activity and good stability for water splitting in alkaline media.At an overpotential of 300 mV,NiFe LDH@CoP/NiP_(3) achieved a current density of 82 mA cm^(-2) for the OER,which was 9.1 and 2.3 times that of CoP/NiP_(3) and NiFe LDH,respectively.Moreover,the reconstruction behavior,during which oxyhydroxides formed,was studied by a combination of X-ray photoelectron spectroscopy,Raman spectroscopy,and scanning electron microscopy.A synergistic effect between NiFe LDH and CoP/NiP_(3) was also observed for the hydrogen evolution reaction.Furthermore,when NiFe LDH@CoP/NiP_(3) acted as both the cathode and anode for overall water splitting,a high current density of 100 mA cm^(-2) was maintained for more than 275 h.In addition,under Xe light irradiation,a solar-to-hydrogen efficiency of 9.89% was achieved for solar-driven water splitting.This work presents the coupling of different active compositions,and can provide a reference for designing bifunctional electrocatalysts.

New method for the determination of convective heat transfer coefficient in fully-developed laminar pipe flow

Convective heat transfer coefficient is one of the most vital parameters which reveals the thermal efficiency of a pipe flow.To obtain such coefficients for problems with variable pipe wall temperature,numerical iterative methods should be used which could be time-consuming and less accurate.In this paper,thermophysical properties of fluids are assumed to be constant.We define a variable related to the temperature gradient of the pipe wall and study the varying law of the local coefficient.Then,a sample-based scheme is proposed to avoid the calculation of a time-consuming problem in the use of solutions with low computing cost.To verify its accuracy,several problems in normal circle pipes with variable factors,such as the various temperatures of the pipe wall,the different radius of the pipe,and various velocities of fluid flow,are well resolved.Meanwhile,its validity in a convergent pipe is also studied.From the obtained results,the high accuracy and efficiency of the proposed scheme can be confirmed.Therefore,the proposed scheme for determining the convective heat transfer coefficient has great potential in engineering problems.

Physicochemical Properties and Gasification Reactivity of the Ultrafine Semi-char derived from a Bench-scale Fluidized Bed Gasifier

Zhtmdong coalfield is the largest intact coalfield worldwide and fluidized bed gasification has been considered as a promising way to achieve its clean and efficient utilization. The purpose of this study is to investigate the phy- sicochemical properties and gasification reactivity of the ultrafme semi-char, derived from a bench-scale fluidized bed gasifier, using Zhundong coal as fuel. The results obtained are as follows. In comparison to the raw coal, the carbon and ash content of the semi-char increase after partial gasification, but the ash fusion temperatures of them show no significant difference. Particularly, 76.53% of the sodium in the feed coal has released to the gas phase after fluidized bed gasification. The chemical compositions of the semi-char are closely related to its particle size, attributable to the distinctly different natures of diverse elements. The semi-char exhibits a higher graphitization degree, higher BET surface area, and richer meso- and macropores, which results in superior gasification reactiv- ity than the coal char. The chemical reactivity of the semi-char is significantly improved by an increased gasifica- tion temperature, which suggests the necessity of regasification of the semi-char at a higher temperature. Conse- quently, it will be considered feasible that these carbons in the semi-char from fluidized bed gasitiers are rec- laimed and reused for the gasification process.

Recent advances in the development of nanomaterials for DC-based immunotherapy

As professional antigen presenting cells, dendritic cells(DCs) greatly determine the quality of the innate and adaptive immunities. Therefore, DC-based immunotherapy has been one of the hotspots in cancer immunotherapy in recent years. Although this unique therapeutic strategy has been approved by U.S. Food and Drug Administration for prostate cancer treatment, the efficacy of DC-based immunotherapy remains to be further improved. Moreover, it is still not completely clear about the immunological basis of DCs, which is another hurdle for the progress of DC-based immunotherapy. Due to their unique physicochemical properties, nanomaterials have shown potentials in addressing these above mentioned problems and have provided important guidelines for optimizing DC-based immunotherapy. However, it is still at the starting stage for this emerging field and there are many critical questions in the rational design of this therapeutic strategy to be answered. Therefore, it is greatly necessary to review and analyze recent progresses in this field. In this review, we mainly focus on the development of various types nanoparticles for DC-based immunotherapy. The existed challenges in this field are also discussed.